GIFT   OF 


DEPARTMENT  OF  COMMERCE 


BUREAU  OF  STANDARDS 


REPORT  PREPARED  FOR 

THE  COMMISSION  OF  THE  UNITED  STATES  OF  AMERICA  TO 
THE  BRAZIL  CENTENNIAL  EXPOSITION 


For  Distribution  at  the  Brazil  Centennial  Exposition 
1922-1923 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1922 


DEPARTMENT  OF  COMMERCE 


BUREAU  OF  STANDARDS 


Supplementing  Exhibit 

of  the 
BUREAU  OF  STANDARDS 

at  the 

BRAZIL  CENTENNIAL  EXPOSITION 

Rio  de  Janeiro,  Brazil 

1922-1923 


By 
WARREN  E.  EMLEY 

United  States  Bureau  of  Standards 


, 


/ 

b 


BUREAU  OF  STANDARDS. 


INTRODUCTION. 

The  Bureau  of  Standards  is  charged  with  the  custody,  maintenance, 
and  intercomparison  of  all  classes  of  standards.  Standards  as  used  in 
this  connection  mean  more  than  the  mere  standards  of  weight  and  meas- 
ure. Thus  there  are  standards  in  the  field  of  electricity,  heat,  optics, 
and  in  fact  in  almost  every  line  of  work.  For  the  purpose  of  organization, 
the  scientific  staff  of  the  bureau  is  divided  into  nine  divisions.  This 
arrangement  is  based  not  on  the  class  of  standards  but  on  the  character 
of  the  work.  Thus  all  experts  in  the  electrical  field  are  grouped  together 
into  what  is  known  as  the  electrical  division.  Experts  in  the  field  of 
weights  and  measures  form  the  weights  and  measures  division,  while 
those  versed  in  temperature  measurements  make  up  the  division  of  heat 
and  thermometry.  A  description  of  the  work  of  each  of  the  divisions 
follows. 

THE   ELECTRICAL   DIVISION. 

As  in  the  case  of  nearly  all  other  kinds  of  work,  one  of  the  most  im- 
portant functions  of  the  bureau  with  respect  to  electricity  and  allied 
subjects  is  the  establishment  and  maintenance  of  the  fundamental  stand- 
ards upon  which  all  electrical  measurements  are  based,  including  coopera- 
tion with  similar  institutions  in  other  countries  so  as  to  secure  inter- 
national uniformity.  This  includes  the  intercomparison  of  standards 
and  extensive  research  in  methods  of  measurement  and  the  development 
and  improvement  of  subsidiary  and  derived  standards.  These  standards 
are  utilized  and  the  results  of  the  researches  are  immediately  applied  in 
the  testing  of  reference  standards  and  instruments  for  manufacturers, 
testing  laboratories,  universities,  research  institutions,  electrical  utilities, 
utility  commissions,  engineering  and  other  interests,  and  various  agencies 
of  the  Government. 

The  testing  of  electrical  instruments  and  apparatus  is  of  two  main 
classes:  First,  there  is  the  standardization  of  reference  standards  and 
precision  instruments  for  manufacturing  and  other  institutions  which 
themselves  make  or  standardize  instruments  for  commercial  use  or  which 
conduct  research  work.  It  is  through  the  work  of  such  institutions  that 
the  measurements  made  in  practice  are  referred  back  to  the  standards 
of  the  bureau.  Second,  a  limited  amount  of  testing  of  commercial  elec- 
trical measuring  instruments  and  devices,  such  as  radio  and  polarimetric 
apparatus,  magnetic  materials,  ignition  appliances,  etc.,  is  done  chiefly 

11938—22 


493808 


OF   STANDARDS. 


for  the;  purpose,  of.  keeping  the  bureau  in  touch  with  the  needs  of  the  in- 
dus.ti'ids;ii  $eve?ofciiig,  improved  methods  of  manufacture,  and  bf  improv- 
ing apparatus  and  materials.  The  greater  portion  of  this  testing  is  done 
for  the  Government  services  and  takes  the  form  of  acceptance  tests  of 
materials  purchased  by  other  Government  departments.  This  work 
serves  the  double  purpose  of  providing  information  to  be  used  in  formulat- 
ing specifications  and  of  determining  the  quality  of  materials  furnished 
in  compliance  with  them.  The  research  work  has  mainly  to  do  with 
methods  of  measurement,  the  determination  of  the  electric  and  magnetic 
properties  of  materials,  and  the  development  of  those  phases  of  electrical 
engineering  in  which  measurement  plays  an  important  role.  Electrical, 
radio,  and  illuminating  engineering  interests  are  all  served  by  these  in- 
vestigations. The  bureau  also  renders  important  service  both  directly 
and  indirectly  to  manufacturing  and  other  industries.  Much  of  this 
investigational  work  is  on  the  more  fundamental  aspects  of  the  principles 
involved,  so  that  the  results  may  be  applicable  to  a  class  of  problems 
rather  than  being  limited  to  the  one  specific  problem  under  investigation. 
Examples  of  this  work  are  to  be  found  in  the  correlation  of  magnetic  and 
mechanical  properties  of  iron  and  steel  and  in  the  study  of  galva- 
nometers. Research  work  in  radio  communication,  magnetism,  radio 
activities,  photometry,  gas  engine  ignition  work,  etc.,  is  along  lines  quite 
similar  to  that  in  the  more  purely  electrical  measurements.  Standards 
have  been  and  are  being  developed,  methods  of  measurements  are  being 
improved,  and  important  special  problems  of  significance  to  the  indus- 
tries— and  in  a  number  of  cases  of  particular  importance  to  the  Govern- 
ment— are  being  investigated. 

One  of  the  valuable  services  which  the  electrical  division  renders 
to  the  Government  and  also  to  the  industries  and  public  is  the  routine 
testing  of  incandescent  electric  lamps.  For  a  number  of  years  all 
Government  purchases  of  this  class  of  material  have  been  based  on 
acceptance  tests  conducted  by  the  bureau.  The  standards  of  manu- 
facture have  thus  been  raised  and  much  valuable  information  has  been 
secured  concerning  the  life  and  efficiency  of  these  lamps.  During  the 
fiscal  year  ended  June  30,  1921,  the  Government  alone  placed  orders 
for  about  3,000,000  incandescent  electric  lamps.  All  these  were  pur- 
chased on  the  basis  of  sample  lamps  tested  at  the  bureau. 

The  testing  of  dry  cells  and  storage  batteries  under  all  conditions 
of  operation  and  the  work  in  standardization  of  sizes  of  dry  cells  is  of 
the  first  importance,  since  almost  everyone  is  a  user  of  such  appliances. 

The  research  work  in  the  field  of  radio  communication  has  yielded 
very  important  results.  The  construction  of  a  satisfactory  form  of 
radio  direction  finder  by  means  of  which  ships  are  able  to  determine 
the  location  of  lighthouses,  etc.,  many  miles  away,  and  when  entirely ' 
obscured  by  distance  and  by  fogs,  would  alone  warrant  a  good  portion 
of  this  investigation. 


BUREAU    OF   STANDARDS.  5 

The  electrical  division  has  carried  out  certain  investigations  which, 
while  not  strictly  electrical  in  their  nature,  are  closely  allied  with  illumina- 
tion or  similar  work.  Among  these  may  be  included  the  investigation 
of  illuminating  and  natural-gas  service  conditions  in  various  cities 
and  States  throughout  the  country,  and  the  investigation  and  tests 
of  all  forms  of  gas  stoves  and  burners.  The  extensive  surveys  which 
the  bureau  has  made  in  these  fields  have  greatly  aided  in  the  estab- 
lishment of  better  relations  between  the  public  service  corporations, 
State  and  municipal  governments,  and  the  public.  A  similar  state- 
ment might  be  made  in  regard  to  the  important  work  on  electrolysis 
mitigation. 

As  mentioned  in  the  portion  of  this  pamphlet  devoted  to  the  bureau's 
relations  to  the  Government  and  the  public,  it  should  be  borne  in  mind 
that  the  assistance  of  an  impartial  third  party  in  the  case  of  disputes, 
such  as  those  referred  to  above,  does  much  more  to  satisfactorily  settle 
the  question  than  long  drawn-out  quarrels  in  the  courts. 

Of  late  years  there  has  been  a  growing  necessity  for  the  standardization 
of  safety  codes  in  our  industrial  establishments.  The  bureau  has  taken 
an  active  part  in  the  unifying  of  such  regulations,  and  a  good  portion  of 
this  work  has  been  assigned  to  the  members  of  the  staff  of  the  electrical 
division. 

Thejtelephone  service  standardization  work  is  also  of  the  first  impor- 
tance and  should  result  in  better  service  and  more  satif sactory  relations 
between  the  telephone  companies  and  the  public. 

THE   DIVISION  OF  WEIGHTS  AND  MEASURES. 

The  original  standardization  work  that  was  carried  out  by  the  ancients 
was  in  connection  with  the  familiar  measurements  of  length  and  mass. 
Standardization  of  these  measurements  is  absolutely  essential  in  any 
civilization,  however  primitive.  The  division  of  weights  and  measures 
may,  therefore,  be  considered  to  deal  with  the  fundamental  work  from 
which  all  the  rest  has  grown. 

This  division  is  charged  with  the  custody  of  the  fundamental  standards 
of  the  United  States.  It  is  probably  not  generally  known  that  we  have 
no  primary  standard  yard  or  pound.  Our  fundamental  standards  of 
length  and  mass  are  the  meter  and  kilogram  which  were  sent  to  this 
country  from  France  by  the  international  bureau  in  1 889.  Our  standard 
yard  and  pound  are  derived  from  these,  which  are  duplicates  of  the 
international  prototypes  kept  at  Paris.  The  working  standards  which 
the  bureau  uses  in  making  comparisons  with  weights  and  measures 
submitted  to  it  for  test  are  compared  at  regular  intervals  with  the 
fundamental  standards  of  the  country,  and  thus  our  measurements  are  in 
reality  referred  back  to  the  standards  deposited  in  the  international 
bureau  at  Paris. 


6  BUREAU    OF   STANDARDS. 

The  bureau  conducts  a  large  number  of  tests  of  sets  of  weights  for 
various  private  and  State  institutions  and  for  the  industries.  As  these 
tests  entail  a  considerable  amount  of  work  and  require  a  great  deal  of 
time,  it  is  not  always  possible  for  the  bureau  to  undertake  all  of  the 
work  of  this  nature  that  it  would  like  to  do.  It  is  therefore  important 
that  its  activities  be  confined  to  the  testing  of  reference  standards,  as  the 
ordinary  routine  testing  of  weights  is  a  problem  which  suitably  belongs  to 
the  commercial  laboratory. 

The  thoroughly  practical  nature  of  the  weights  and  measures  work 
will  be  appreciated  when  one  learns  that  the  bureau  has  two  well-equipped 
cars  for  calibrating  railroad  track  scales.  These  cars  are  high-capacity 
box  cars,  specially  constructed  to  hold  a  set  of  weights,  with  a  total  weight 
of  100,000  pounds.  By  means  of  a  crane  attached  to  the  car  and  oper- 
ated by  a  gasoline  engine  these  weights  can  be  loaded  onto  the  scale  and 
its  reading  compared  with  the  actual  load  placed  upon  it.  Such  an  equip- 
ment is  much  more  accurate  and  reliable  than  the  ordinary  single  dead- 
weight test  car  which  most  railroads  use  for  this  purpose.  The  bureau, 
however,  also  owns  some  cars  of  this  type  for  less  accurate  work.  The 
weights  in  the  larger  test  cars  just  mentioned  are  well  protected  inside 
the  car  and  are  not  subject  to  the  wear  and  consequent  variation  which 
is  bound  to  occur  in  the  case  where  the  car  itself  is  used  as  the  weight. 

For  the  inspection  and  calibration  of  mine  scales,  which  in  many  cases 
are  located  in  almost  inaccessible  territory,  the  bureau  maintains  spe- 
cially built  motor  trucks  which  serve  the  same  purpose  (to  transport 
dead  weights)  as  the  cars  mentioned  above.  These  mine-scale  testing 
equipments  have  done  a  great  service  in  aiding  to  settle  disputes  between 
mine  operators  and  the  workers  and  in. assuring  the  giving  of  honest 
weights  to  the  consumer. 

During  the  war  munitions  were  produced  in  vast  quantities  in  this 
country.  The  making  of  shells  and  similar  articles  on  an  absolutely 
interchangeable  basis  required  the  use  of  a  great  number  of  accurate 
gauges.  The  bureau  took  a  leading  part  in  assisting  the  military  depart- 
ments in  this  work.  Its  assistance  took  not  only  the  form  of  routine 
testing  of  large  numbers  of  gauges  but  also  the  manufacture  of  gauge 
blocks,  an  industry  theretofore  confined  entirely  to  one  firm  in  Europe. 
This  process  has  now  been  perfected  and  adopted  by  one  of  the  leading 
makers  of  precision  tools  in  the  United  States. 

One  of  the  laboratories  of  the  weights  and  measures  division  is  devoted 
to  the  testing  of  clocks  and  watches.  This  work  has  grown  from  small 
proportions  before  the  war  to  quite  an  important  part  of  the  bureau's 
activities.  Many  hundreds  of  clocks  and  watches  have  been  tested  for 
the  United  States  Shipping  Board  an*d  the  War  Department.  Until 
recently  no  ship's  chronometers  were  made  in  this  country,  but  it  is 
likely  that  since  the  need  for  such  articles  has  been  recognized  the  indus- 
try will  obtain  a  footing  in  the  United  States.  In  this  development 


BUREAU    OF   STANDARDS.  7 

work  the  bureau  has  played  an  important  part.  Other  laboratories  are 
devoted  to  the  testing  of  volumetric  glassware,  large  quantities  of  which 
are  constantly  submitted  to  the  bureau  for  test  and  certification. 

THE   DIVISION    OF    HEAT   AND   THERMOMETRY. 

An  idea  of  a  portion  of  the  work  of  this  division  is  quite  evident  from 
its  title,  but  the  breadth  of  the  field  covered  in  the  study  of  the  phenomena 
of  heat  is  probably  not  appreciated  by  the  average  nonscientific  man.  It 
is  true  that  a  large  part  of  the  work  of  this  division  consists  of  the  cali- 
bration of  thermometers  of  all  sorts,  as  may  be  judged  from  the  com- 
pleteness of  the  thermometer  laboratory.  The  bureau's  work  in  aiding 
to  place  the  manufacture  of  clinical  thermometers  on  a  more  scientific 
and  honest  basis  has  been  of  great  importance.  The  work  is  much 
broader  than  this,  however,  and  includes  investigations  of  the  melting 
points  of  various  materials  and  the  establishment  of  fixed  points  on  the 
high  temperature  thermometric  scale.  Such  work  requires  the  use  of  a 
great  deal  of  special  apparatus  and  the  highest  degree  of  scientific  ability. 
It  is  of  great  importance  in  many  of  the  industries  which  are  dependent 
upon  the  accurate  control  of  very  high  temperatures. 

Standard  samples  for  use  in  calorimetric  work  are  distributed  by  the 
bureau  and  serve  as  reference  standards  in  the  industries. 

The  production  of  extremely  low  temperatures  and  the  liquefaction 
of  air  and  hydrogen  and  ultimately  of  helium  is  carried  on  by  this  division. 
The  plant  provided  for  this  purpose  is  a  very  complete  one  and  is  operated 
once  or  twice  a  week  to  maintain  the  necessary  quantities  of  liquid  air 
in  stock.  Valuable  assistance  to  the  refrigerating  industries  has  been 
given  through  the  investigations  conducted  by  the  heat  division. 

An  interesting  part  of  the  work  of  this  division  is  that  concerned  with 
the  investigation  of  internal-combustion  engines,  particularly  those  used 
for  automobiles  and  airplanes.  Prior  to  the  establishment  of  the  bureau's 
laboratory  for  this  purpose,  no  testing  of  such  engines  under  conditions 
comparable  to  those  of  actual  service  had  been  carried  out.  The  bureau 
constructed  a  special  laboratory  containing  a  chamber  within  which  an 
airplane  engine  could  be  placed  and  operated  under  the  conditions  of  low 
atmospheric  pressure  and  temperature  met  with  at  the  high  altitudes  at 
which  planes  often  fly.  This  work  was  of  great  value  to  our  Air  Service 
during  the  war.  Extensive,  investigational  and  development  work  on 
automobile  engines  and  appliances,  including  the  testing  of  cars  on  the 
road,  has  likewise  been  conducted.  The  results  obtained  in  these  tests 
are  of  great  value  to  engine  designers  and  will  result  in  a  better  utilization 
of  gasoline  and  in  a  better 'running  automobile. 

The  determination  of  the  fireproofing  qualities  of  various  materials  is 
of  great  importance  in  building  construction,  and  this  division,  in  coopera- 
tion with  various  organizations,  has  conducted  a  thorough  investigation 
of  numerous  fireproofing  materials,  fireproof  coatings  for  building  columns, 


8  BUBpAU   OF   STANDARDS. 

etc.  Results  of  great  value  have  been  obtained,  and  it  is  thought  that 
considerable  aid  will  be  given  to  architects  and  engineers  through  this 
work. 

THE   OPTICAL,  DIVISION. 

Optical  instruments  and  optical  methods  are  used  in  nearly  all  branches 
of  science  and  the  purely  scientific  investigations  carried  out  in  the  labora- 
tory often  have  an  important  application  in  practical  work.  One  of  the 
sections  of  this  division  is  engaged  with  the  study  of  spectroscopy — that 
is,  the  determination  of  the  spectra  of  the  various  chemical  elements. 
Such  work  is  of  great  importance  in  the  analysis  of  certain  substances 
and  is  being  used  to  a  greater  extent  each  year  in  the  industries.  In 
connection  with  spectroscopy,  the  bureau  developed  some  special  photo- 
graphic plates  which  were  sensitive  to  the  longer  or  red  waves  of  the  spec- 
trum. As  showing  how  a  scientific  achievement  may  very  often  have 
an  intensely  practical  application,  photographic  plates  developed  in 
connection  with  spectroscopic  analysis  proved  to  be  the  best  obtainable 
plates  for  aerial  photography.  By  using  such  plates  photographs  could 
be  taken  through  haze,  smoke,  and  clouds  which  might  happen  to  be 
below  the  airplane.  Camouflaged  objects  were  also  easily  distinguished, 
owing  to  the  fact  that,  when  photographed  on  these  specially  sensitized 
plates  through  a  suitable  color  screen,  the  colors,  while  looking  the  same 
to  the  naked  eye,  had  a  distinctly  different  appearance. 

Another  optical  field  of  great  importance  to  the  industries  is  that  of 
polarimetry.  As  the  polarimetric  examination  of  sugar  is  one  of  the 
most  important  tests  of  that  commodity,  the  bureau  has  undertaken  the 
work  of  standardizing  and  in  certain  cases  of  adjusting  polariscopes 
submitted  to  it  by  the  sugar  refiners.  In  this  way  it  has  been  of  real 
benefit  to  this  industry,  as  such  instruments  could  not  be  readily  procured 
during  the  war  and  many  tl\at  were  in  use  were  in  bad  condition.  The 
bureau's  laboratories  have  produced  a  number  of  the  rare  sugars  for 
medical  and  other  work. 

The  section  of  the  bureau  devoted  to  colorimetry  carries  on  some 
important  work.  The  study  of  colors  and  color  standards  is  of  great 
importance  in  many  lines  of  industry.  Many  kinds  of  oils  and  other 
liquids  are  sold  on  the  basis  of  color,  and  the  use  of  accurate  standards 
in  this  work  is  of  the  first  importance.  This  section  is  also  engaged 
in  the  testing  of  eye-protective  glasses,  such  as  are  used  by  workmen 
to  guard  their  eyes  from  injurious  radiations.  The  bureau  has  found 
that  many  of  the  glasses  ordinarily  sold  are  of  little  value  for  such  use, 
while  others  are  quite  satisfactory.  Its  work  in  this  field  is  of  very- 
great  and  direct  benefit  to  the  country.  Its  work  on  the  colored  glasses 
used  for  railway  signal  lights  should  also  be  mentioned.  During  the 
war  a  number  of  special  investigations  concerned  with  colorimetry 
were  carried  out,  such  as  a  means  for  signaling  by  invisible  radiations, 


BUREAU   OF   STANDARDS.  9 

varipus  methods  for  the  detection  of  invisible  writing,  and  color- 
camouflaged  signaling  devices.  An  elaborate  investigation  of  high- 
power  military  searchlights  was  initiated  during  the  war  and  is  still  in 
progress;  it  includes  the  complete  investigation  of  the  light  source  in 
such  lamps  and  the  distribution  of  illumination  throughout  the  beam. 

Another  section  of  this  division  deals  with  optical  instruments  and 
has  devoted  a  great  deal  of  time  to  the  study  of  the  design  of  this  class 
of  apparatus.  Nearly  all  these  instruments  were  previously  made 
abroad,  but  a  number  of  American  firms  are  now  entering  the  field, 
and  it  is  the  desire  of  the  bureau  to  assist  them  in  every  way  possible. 
A  great  many  binoculars  and  other  optical  devices  were  required  by 
the  military  and  naval  branches  of  the  Government  service  during 
the  war.  Nearly  all  of  such  instruments  were  first  tested  by  the  bureau 
and  rapid  but  accurate  methods  of  determining  the  constants  of  optical 
instruments  were  perfected  in  this  laboratory. 

The  use  of  radiometry  for  purposes  of  secret  signaling  was  a  system 
developed  during  the  war  and  which  has  been  carried  by  the  bureau  to  a 
practical  point. 

Interferometry,  or  the  interference  of  light  waves,  has  been  used  to 
measure .  small  changes  of  length,  and  plays  an  important  part  in  the 
testing  of  extremely  accurate  gauges,  such  as  were  used  in  the  production 
of  munitions.  In  this  work  the  optical  division  cooperated  closely  with 
the  division  of  weights  and  measures,  and  also  with  the  military 
departments. 

THE   CHEMISTRY   DIVISION. 

We  have  already  mentioned  in  this  pamphlet  that  a  great  deal  of  the 
work  of  the  chemistry  division  is  in  cooperation  with  the  other  eight 
scientific  divisions  of  the  bureau.  Many  of  the  problems  which  come 
to  the  bureau  for  solution  demand  chemical  analyses  as  a  part  of  the  work. 
It  must  not  be  inferred,  however,  that  the  chemistry  division  does  not 
initiate  and  deal  with  many  independent  investigations.  It  likewise 
carries  on  many  tests  purely  chemical  in  their  nature  for  other  Govern- 
ment departments  and  in  some  cases  for  municipal  institutions  and  private 
parties.  It  also  distributes  many  standard  samples  of  various  materials 
which  are  used  for  reference  purposes  in  the  industries.  This  work  alone 
is  of  the  greatest  importance.  In  certain  of  the  work  carried  on  by  the 
bureau  absolutely  pure  substances  are  necessary,  and  the  preparation 
of  these  forms  a  part  of  the  activities  of  the  chemistry  division. 

The  field  of  electrochemistry  is  becoming  more  important  each  year, 
and  in  the  solution  of  such  problems  the  bureau  has  taken  an  active  part. 
Accurate  data  are  lacking  on  a  good  many  of  the  processes  of  electro- 
plating, and  the  work  of  the  chemical  division  has  been  of  real  assistance 
to  this  industry. 


10  BUREAU    OF   STANDARDS. 

In  the  case  of  the  section  on  metals  and  ore  analysis,  the  work  is  carried 
on  in  cooperation  with  the  metallurgical  division,  the  two  being  very 
closely  related. 

Another  section  devoted  to  gas  chemistry  has  been  largely  employed 
during  the  past  few  years  on  the  testing  and  investigation  of  the  prop- 
erties of  balloon  fabrics  and  the  development  of  automatic  gas  analysis 
apparatus.  This  latter  work  has  been  of  great  importance  to  the  nitrate 
division  of  the  Ordnance  Department  of  the  Army  and  was  used  in  analyz- 
ing the  gas  for  balloon  purposes  obtained  from  the  Government's  helium 
plants. 

In  connection  with  the  study  of  reagents  and  chemical  apparatus 
the  bureau  has  been  actively  employed  in  testing  various  substitutes  for 
platinum  ordinarily  used  in  the  making  of  certain  chemical  vessels  and 
in  the  production  of  platinum  of  unusual  purity.  A  great  many  tests 
have  been  carried  out  by  the  bureau  on  platinum  substitutes,  but  none 
have  been  found  which  can  entirely  replace  platinum  for  certain  uses. 

Chemical  work  enters  into  all  the  investigations  of  such  substances  as 
lubricating  oils,  rubber,  leather,  paper,  textiles,  ink,  glue,  etc.  In  this 
work  the  chemical  division  performs  the  analytical  tests,  while  the 
physical  strength  and  other  investigations  are  handled*  by  the  division 
of  structural,  miscellaneous,  and  engineering  materials. 

Chemical  work  is  also  important  in  the  testing  of  cement,  bituminous 
materials,  paint,  varnishes,  and  soap.  The  Government  is  a  large  buyer 
of  all  classes  of  these  substances,  and  nearly  all  of  the  acceptance  tests, 
to  determine  whether  the  article  supplied  complies  with  the  Government 
specifications,  are  performed  by  the  chemical  division  of  the  bureau. 

ENGINEERING   PHYSICS. 

While  this  division  is  one  of  the  newer  ones  of  the  bureau,  its  work  is, 
nevertheless,  of  great  variety  and  importance.  It  includes  the  testing 
of  such  appliances  as  water  current  meters,  ventilators,  fire  extinguishers 
pressure  gauges,  fittings  for  heating  systems,  aeronautic  and  similar 
measuring  instruments,  the  determination  of  the  aerodynamical  proper- 
ties of  model  airplanes  in  the  bureau's  wind  tunnels,  and  the  study  of 
sound  and  allied  subjects.  The  last-named  work  is  very  important  to 
the  architect  and  user  of  building  materials,  since  sound-proofness  and 
sound  transmission  are  important  matters  in  the  design  of  structures. 
Two  of  the  three  wind  tunnels  belonging  to  this  division  give  an  air  speed 
of  90  miles  per  hour,  while  190  miles  per  hour  may  be  obtained  in  the 
third.  The  balances  on  which  the  specimens  are  mounted  are  designed 
to  care  for  all  sorts  of  work,  from  the  testing  of  very  heavy  specimens, 
such  as  sections  of  airplane  radiators,  to  the  finest  and  most  accurate 
kind  of  work  on  model  aerofoils,  etc. 

The  tests  of  aeronautic  instruments  really  serve  to  place  the  manufac- 
ture of  such  devices  on  an  accurate  basis,  as  but  little  work  had  been  done 


BUREAU   OF   STANDARDS.  II 

in  the  field  when  the  bureau  started  its  investigations.  Since  the  war 
this  section  has  devoted  itself  to  somewhat  similar  problems  along  broader 
lines. 

STRUCTURAL,    MISCELLANEOUS,    AND   ENGINEERING   MATERIALS. 

This  division  is  preeminently  the  industrial  division  of  the  bureau.  Its 
work  is  carried  on  in  close  cooperation  with  the  various  industries  of  the 
country  and  includes  the  investigation  and  testing  of  the  ordinary  mate- 
rials used  for  constructional  work  and  in  the  making  of  rubber  and  leather 
goods,  textiles,  and  paper. 

One  section  is  devoted  to  the  testing  of  metals  and  wood  and  is 
equipped  with  machines  capable  of  determining  the  properties  of  any 
size  specimen  from  the  lightest  piece  of  wood  to  a  full-size  steel  column. 
One  of  the  emery-testing  machines  which  is  assigned  to  this  section  is 
the  largest  precision  testing  machine  in  the  world.  It  has  a  capacity 
of  2,300,000  pounds  in  compression  and  about  one-half  that  in  tension. 
It  is  so  designed  that  both  tensile  and  compressive  strength  tests  can 
be  carried  out  with  the  highest  degree  of  accuracy  and  with  the  maximum 
of  convenience.  Besides  this  machine,  the  bureau  owns  a  still  larger 
compression  testing  machine  having  a  total  capacity  of  10,000,000 
pounds.  This  is  at  present  located  in  the  branch  laboratory  of  the 
Bureau  of  Standards  at  Pittsburgh,  Pa.,  but  it  is  the  intention  to  move 
it  to  the  Washington  plant  as  soon  as  opportunity  permits.  The  me- 
chanical equipment  of  this  section  includes,  besides  the  tensile  and 
compressive  machines  just  mentioned,  a  full  assortment  of  torsional, 
cross  bend,  impact,  and  hardness  testing  machines. 

The  investigation  of  airplane  woods  conducted  by  this  section  before 
and  during  the  war  is  the  most  complete  ever  attempted.  Its  service 
to  the  Government  consists  in  a  large  amount  of  routine  testing  of 
steel  and  other  substances  and  in  certain  investigations  requiring  the 
accurate  determination  of  the  physical  properties  of  materials. 

The  second  section  of  this  division  deals  with  investigations  of  cement 
and  concrete.  It  is  equipped  to  carry  out  work  both  in  the  laboratory 
and  in  the  field,  and  conducts  at  all  times  a  great  number  of  routine 
tests  of  cement  used  in  governmental  construction  work.  This  part  of 
the  bureau's  work  assumed  such  large  proportions  during  the  war  that 
it  was  necessary  to  establish  a  number  of  branch  laboratories  devoted 
to  cement  testing.  These  greatly  aided  the  Government  in  rapidly 
carrying  out  its  program  in  the  construction  of  wharves,  warehouses, 
cantonments,  etc.  The  investigational  work  on  cement  and  concrete 
during  the  war  was  quite  largely  devoted  to  the  perfecting  of  a  par- 
ticularly light  and  strong  concrete  for  use  in  ship  construction.  Through 
the  bureau's  efforts,  and  by  the  use  of  a  so-called  light-weight  aggregate, 
a  concrete  giving  a  strength  many  times  that  usually  obtained  in  build- 
ing construction  was  produced,  thus  enabling  the  United  States  Ship- 


12  BUREAU   OF   STANDARDS. 

ping  Board  to  build  concrete  vessels  of  maximum  carrying  capacity 
with  minimum  weight. 

Closely  allied  to  the  work  on  cement  and  concrete  is  that  conducted 
by  the  bureau  on  lime  and  similar  material.  This  work  includes  inves- 
tigations of  the  effect  of  different  kinds  of  lime  upon  the  properties  of 
concrete,  possible  ways  for  the  improving  of  the  quality  of  lime  plaster, 
and  investigations  of  the  best  means  for  manufacturing  sand-lime 
brick.  Some  work  has  also  been  done  on  the  use  of  reinforced  gypsum 
and  means  has  been  developed  whereby  the  strength  and  waterproof- 
ness  of  this  material  may  be  increased. 

Other  sections  of  this  division  are  concerned  with  the  physical  testing 
of  rubber,  leather,  textiles,  and  paper.  This  work  necessarily  requires 
familiarity  with  all  of  the  manufacturing  processes  used  in  the  produc- 
tion of  the  finished  articles  and  in  order  to  enable  the  bureau  to  test  the 
relative  merits  of  various  manufacturing  processes  a  small  size  but  com- 
plete rubber  mill  and  paper  mill  have  been  provided.  The  textile  section 
is  quite  completely  equipped  with  cotton  mill  machinery  and  a  number  of 
special  appliances  for  the  rapid  and  accurate  testing  of  cloths. 

A  constant-humidity  room  for  testing  paper  and  textiles  under  accu- 
rately controlled  conditions  forms  part  of  the  unusual  equipment  of  this 
division. 

THE   METALLURGICAL   DIVISION. 

This  division  is  concerned  with  the  thermal  analysis  and  structure  of 
metals,  heat  treatment  and  its  effect  upon  metals  and  alloys,  including 
the  researches  involved  in  determining  the  causes  of  metal  failures,  the 
study  of  heating  and  cooling  curves,  the  investigation  of  hardening,  an- 
nealing, tempering,  cementation,  determination  of  the  critical  ranges, 
and  the  preparation  of  pure  metals  and  alloys*  In  connection  with  this 
division  one  of  the  few  experimental  foundries  in  existence  is  operated. 
This  is  equipped  with  furnaces  suitable  for  the  melting  of  both  ferrous 
and  nonferrous  alloys.  Besides  being  employed  in  investigational  work, 
it  runs  out  quite  a  number  of  castings  used  in  the  bureau's  machine  shops 
for  the  construction  of  special  apparatus.  Foundry  practice  in  connec- 
tion with  various  kinds  of  metals  can  thus  be  studied  and  a  great  deal  of 
valuable  information  is  also  obtained  concerning  furnace  behavior,  the 
relative  merits  of  various  types  of  foundry  sands,  etc.  For  studying  the 
numerous  phases  of  the  working  of  metals,  a  small-size  electrically 
driven  rolling  mill,  a  forging  press,  and  other  similar  equipment  has  been 
installed.  The  laboratory  devoted  to  microphotographic  work,  in  con- 
nection with  the  microscopy  and  structure  of 'metals,  is  unusually  com- 
plete. Valuable  work  has  been  done  here  on  the  causes  of  failure  of  rail- 
road rails  and  similar  important  problems.  An  experimental  heat-treat- 
ing plant  in  which  the  effects  of  high  temperatures  on  various  alloys  of 
steel  can  be  studied  is  maintained  by  this  division.  Many  special  inves- 


BUREAU    OF   STANDARDS.  13 

tigations,  such  as  the  determination  of  the  causes  of  failure  of  car  wheels, 
are  continually  carried  on  for  the  benefit  of  metallurgical  industries  of 
the  country.  In  cooperation  with  the  chemical  division,  analyses  of 
metals  are  conducted  and  pure  metals  and  alloys  are  produced  for  scien- 
tific purposes. 

A  great  deal  of  investigational  work  is  carried  on  in  this  division  to 
determine  the  best  composition  for  brass,  copper,  bronze,  and  similar 
materials  needed  by  other  departments  of  the  Government. 

THE  CERAMICS  DIVISION. 

The  first  section  of  this  division  is  concerned  with  clay  products,  the 
development  of  new  uses  for  clay,  the  replacement  of  imported  by  native 
materials,  improvement  of  the  quality  of  clay  products,  and  in  making 
routine  tests  for  the  Government  involving  the  use  of  clays  and  similar 
materials. 

An  important  work  of  this  division  is  in  connection  with  refractories 
of  all  sorts  for  use  in  furnaces  and  other  places  where  high  temperatures 
must  be  withstood.  In  cooperation  with  the  section  devoted  to  the 
manufacture  of  optical  glass,  a  special  form  of  glass  pot  has  been  developed 
using  for  the  material  a  refuse  from  earthenware  and  wall  tile  manufactur- 
ing plants.  The  use  of  these  pots  promises  to  revolutionize  one  portion 
of  the  optical  industry,  and  they  are  already  employed  commercially 
by  several  glass  makers. 

Strength  tests  are  conducted  on  hollow-tile  walls  and  construction, 
using  architectural  terra  cotta  and  similar  materials,  and  in  cooperation 
with  Division  III,  considerable  work  has  been  done  on  the  investigation 
of  fire-resisting  protective  coatings  for  building  columns. 

Section  2  of  the  ceramic  division  is  devoted  to  the  manufacture  of 
optical  glass.  It  should  be  noted  that  only  a  few  years  ago  not  a  pound 
of  optical  glass  was  produced  in  the  United  States ;  all  of  it  was  imported 
from  a  few  firms  in  Germany,  France,  and  England.  The  bureau  fore- 
saw that  in  the  event  of  an  emergency  this  supply  might  be  greatly 
curtailed.  After  the  commencement  of  the  war  in  Europe  the  bureau 
undertook  a  complete  study  of  the  manufacture  of  this  kind  of  glass 
and  at  the  time  the  United  States  entered  the  conflict  it  had  worked  out 
a  satisfactory  process  for  producing  the  ordinary  grades  of  optical  glass. 
It  was  only  after  a  long  and  exhaustive  investigation  that  the  proper 
technique  for  the  operation  of  the  furnace,  the  best  design  and  most 
satisfactory  materials  for  use  in  constructing  the  glass  pots,  etc.,  could 
be  worked  out,  and  the  final  result — the  production  of  high-grade  optical 
glass — is  one  of  the  most  important  accomplishments  of  the  bureau. 
This  work  has  all  been  conducted  in  the  closest  cooperation  with  and 
for  the  benefit  of  the  American  glass  industry.  The  results  have  been 
freely  given  to  all  those  interested,  and  several  firms  are  now  manufactur- 
ing a  good  grade  of  optical  glass. 


14  BUREAU   OF   STANDARDS. 

Another  section  of  the  ceramics  division  is  concerned  with  the  study 
of  enamels  for  use  on  metal  ware.  The  production  of  satisfactory 
enamels  for  this  purpose  was  an  art  previously  known  only  in  Europe,  and 
the  development  of  satisfactory  processes  in  the  United  States  is  of 
extreme  importance.  While  the  work  has  not  been  under  way  for  any 
great  length  of  time,  important  results  have  already  been  brought  about, 
and  it  is  believed  that  eventually  an  enamel  in  every  way  as  satisfactory 
as  that  produced  abroad  will  be  developed. 

o 


14  DAY  USE 

•URN  TO  DESK  FROM  WHICH  BORROWED 
LOAN  DEPT. 


This  book  is  due  on  the  last  date  stamped  below  or 

on  the  date  to  which  renewed 
Renewed  books  are  subject  to  immediate  recall. 


AUTO  DISC  CIRC  f 


.  General  Library 

University  of  California 

Berkeley 


LD  21A-50m-8  '57 
(C8481slO)476B 


Gaylord  Bros. 

Makers 

Syracuse,  N.  V. 
PAT.  JAN.  21,  1908 


493808 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


U.C.BERKELEY  LIBRARIES 


